FreeBSD/Linux Kernel Cross Reference
sys/netinet6/in6_fib_algo.c

     /*-
      * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
      *
      * Copyright (c) 2020 Alexander V. Chernikov
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
      * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    #include "opt_inet6.h"
    
    #include <sys/param.h>
    #include <sys/eventhandler.h>
    #include <sys/kernel.h>
    #include <sys/lock.h>
    #include <sys/rmlock.h>
    #include <sys/malloc.h>
    #include <sys/mbuf.h>
    #include <sys/module.h>
    #include <sys/kernel.h>
    #include <sys/priv.h>
    #include <sys/proc.h>
    #include <sys/socket.h>
    #include <sys/socketvar.h>
    #include <sys/sysctl.h>
    #include <net/vnet.h>
    
    #include <net/if.h>
    #include <net/if_var.h>
    
    #include <netinet/in.h>
    #include <netinet/in_var.h>
    #include <netinet/ip.h>
    #include <netinet/ip_var.h>
    #include <netinet/ip6.h>
    #include <netinet6/ip6_var.h>
    #include <netinet6/in6_fib.h>
    
    #include <net/route.h>
    #include <net/route/nhop.h>
    #include <net/route/route_ctl.h>
    #include <net/route/route_var.h>
    #include <net/route/fib_algo.h>
    
    /*
     * Lockless radix lookup algo.
     *
     * Compiles immutable radix from the current routing table.
     * Used with small amount of routes (<1000).
     * As datastructure is immutable, it gets rebuild on each rtable change.
     *
     */
    
    #define KEY_LEN_INET6   (offsetof(struct sa_in6, sin6_addr) + sizeof(struct in6_addr))
    #define OFF_LEN_INET6   (8 * offsetof(struct sa_in6, sin6_addr))
    struct sa_in6 {
            uint8_t                 sin6_len;
            uint8_t                 sin6_family;
            uint8_t                 pad[6];
            struct in6_addr         sin6_addr;
    };
    struct radix6_addr_entry {
            struct radix_node       rn[2];
            struct sa_in6           addr;
            struct nhop_object      *nhop;
    };
    #define LRADIX6_ITEM_SZ roundup2(sizeof(struct radix6_addr_entry), CACHE_LINE_SIZE)
    
    struct lradix6_data {
            struct radix_node_head  *rnh;
            struct fib_data         *fd;
            void                    *mem; // raw radix_mem pointer to free
            void                    *radix_mem;
            uint32_t                alloc_items;
            uint32_t                num_items;
    };
    
    static struct nhop_object *
    lradix6_lookup(void *algo_data, const struct flm_lookup_key key, uint32_t scopeid)
   {
           struct radix_node_head *rnh = (struct radix_node_head *)algo_data;
           struct radix6_addr_entry *ent;
           struct sa_in6 addr6 = {
                   .sin6_len = KEY_LEN_INET6,
                   .sin6_addr = *key.addr6,
           };
           if (IN6_IS_SCOPE_LINKLOCAL(key.addr6))
                   addr6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
           ent = (struct radix6_addr_entry *)(rn_match(&addr6, &rnh->rh));
           if (ent != NULL)
                   return (ent->nhop);
           return (NULL);
   }
   
   static uint8_t
   lradix6_get_pref(const struct rib_rtable_info *rinfo)
   {
   
           if (rinfo->num_prefixes < 10)
                   return (255);
           else if (rinfo->num_prefixes < 10000)
                   return (255 - rinfo->num_prefixes / 40);
           else
                   return (1);
   }
   
   static enum flm_op_result
   lradix6_init(uint32_t fibnum, struct fib_data *fd, void *_old_data, void **_data)
   {
           struct lradix6_data *lr;
           struct rib_rtable_info rinfo;
           uint32_t count;
           void *mem;
    
           lr = malloc(sizeof(struct lradix6_data), M_RTABLE, M_NOWAIT | M_ZERO);
           if (lr == NULL || !rn_inithead((void **)&lr->rnh, OFF_LEN_INET6))
                   return (FLM_REBUILD);
           fib_get_rtable_info(fib_get_rh(fd), &rinfo);
   
           count = rinfo.num_prefixes * 11 / 10;
           // count+1 adds at least 1 cache line
           mem = malloc((count + 1) * LRADIX6_ITEM_SZ, M_RTABLE, M_NOWAIT | M_ZERO);
           if (mem == NULL)
                   return (FLM_REBUILD);
           lr->mem = mem;
           lr->radix_mem = (void *)roundup2((uintptr_t)mem, CACHE_LINE_SIZE);
           lr->alloc_items = count;
           lr->fd = fd;
   
           *_data = lr;
   
           return (FLM_SUCCESS);
   }
   
   static void
   lradix6_destroy(void *_data)
   {
           struct lradix6_data *lr = (struct lradix6_data *)_data;
   
           if (lr->rnh != NULL)
                   rn_detachhead((void **)&lr->rnh);
           if (lr->mem != NULL)
                   free(lr->mem, M_RTABLE);
           free(lr, M_RTABLE);
   }
   
   static enum flm_op_result
   lradix6_add_route_cb(struct rtentry *rt, void *_data)
   {
           struct lradix6_data *lr = (struct lradix6_data *)_data;
           struct radix6_addr_entry *ae;
           struct sockaddr_in6 *rt_dst, *rt_mask;
           struct sa_in6 mask;
           struct radix_node *rn;
           struct nhop_object *nh;
   
           nh = rt_get_raw_nhop(rt);
   
           if (lr->num_items >= lr->alloc_items)
                   return (FLM_REBUILD);
   
           ae = (struct radix6_addr_entry *)((char *)lr->radix_mem + lr->num_items * LRADIX6_ITEM_SZ);
           lr->num_items++;
   
           ae->nhop = nh;
   
           rt_dst = (struct sockaddr_in6 *)rt_key(rt);
           rt_mask = (struct sockaddr_in6 *)rt_mask(rt);
   
           ae->addr.sin6_len = KEY_LEN_INET6;
           ae->addr.sin6_addr = rt_dst->sin6_addr;
   
           if (rt_mask != NULL) {
                   bzero(&mask, sizeof(mask));
                   mask.sin6_len = KEY_LEN_INET6;
                   mask.sin6_addr = rt_mask->sin6_addr;
                   rt_mask = (struct sockaddr_in6 *)&mask;
           }
   
           rn = lr->rnh->rnh_addaddr((struct sockaddr *)&ae->addr,
               (struct sockaddr *)rt_mask, &lr->rnh->rh, ae->rn);
           if (rn == NULL)
                   return (FLM_REBUILD);
   
           return (FLM_SUCCESS);
   }
   
   static enum flm_op_result
   lradix6_end_dump(void *_data, struct fib_dp *dp)
   {
           struct lradix6_data *lr = (struct lradix6_data *)_data;
   
           dp->f = lradix6_lookup;
           dp->arg = lr->rnh;
   
           return (FLM_SUCCESS);
   }
   
   static enum flm_op_result
   lradix6_change_cb(struct rib_head *rnh, struct rib_cmd_info *rc,
       void *_data)
   {
   
           return (FLM_REBUILD);
   }
   
   struct fib_lookup_module flm_radix6_lockless = {
           .flm_name = "radix6_lockless",
           .flm_family = AF_INET6,
           .flm_init_cb = lradix6_init,
           .flm_destroy_cb = lradix6_destroy,
           .flm_dump_rib_item_cb = lradix6_add_route_cb,
           .flm_dump_end_cb = lradix6_end_dump,
           .flm_change_rib_item_cb = lradix6_change_cb,
           .flm_get_pref = lradix6_get_pref,
   };
   
   /*
    * Fallback lookup algorithm.
    * This is a simple wrapper around system radix.
    */
   
   struct radix6_data {
           struct fib_data *fd;
           struct rib_head *rh;
   };
   
   static struct nhop_object *
   radix6_lookup(void *algo_data, const struct flm_lookup_key key, uint32_t scopeid)
   {
           RIB_RLOCK_TRACKER;
           struct rib_head *rh = (struct rib_head *)algo_data;
           struct radix_node *rn;
           struct nhop_object *nh;
   
           /* Prepare lookup key */
           struct sockaddr_in6 sin6 = {
                   .sin6_family = AF_INET6,
                   .sin6_len = sizeof(struct sockaddr_in6),
                   .sin6_addr = *key.addr6,
           };
           if (IN6_IS_SCOPE_LINKLOCAL(key.addr6))
                   sin6.sin6_addr.s6_addr16[1] = htons(scopeid & 0xffff);
   
           nh = NULL;
           RIB_RLOCK(rh);
           rn = rn_match((void *)&sin6, &rh->head);
           if (rn != NULL && ((rn->rn_flags & RNF_ROOT) == 0))
                   nh = (RNTORT(rn))->rt_nhop;
           RIB_RUNLOCK(rh);
   
           return (nh);
   }
   
   struct nhop_object *
   fib6_radix_lookup_nh(uint32_t fibnum, const struct in6_addr *dst6, uint32_t scopeid)
   {
           struct rib_head *rh = rh = rt_tables_get_rnh(fibnum, AF_INET6);
           const struct flm_lookup_key key = { .addr6 = dst6 };
   
           if (rh == NULL)
                   return (NULL);
   
           return (radix6_lookup(rh, key, scopeid));
   }
   
   static uint8_t
   radix6_get_pref(const struct rib_rtable_info *rinfo)
   {
   
           return (50);
   }
   
   static enum flm_op_result
   radix6_init(uint32_t fibnum, struct fib_data *fd, void *_old_data, void **_data)
   {
           struct radix6_data *r6;
   
           r6 = malloc(sizeof(struct radix6_data), M_RTABLE, M_NOWAIT | M_ZERO);
           if (r6 == NULL)
                   return (FLM_REBUILD);
           r6->fd = fd;
           r6->rh = fib_get_rh(fd);
   
           *_data = r6;
   
           return (FLM_SUCCESS);
   }
   
   static void
   radix6_destroy(void *_data)
   {
   
           free(_data, M_RTABLE);
   }
   
   static enum flm_op_result
   radix6_add_route_cb(struct rtentry *rt, void *_data)
   {
   
           return (FLM_SUCCESS);
   }
   
   static enum flm_op_result
   radix6_end_dump(void *_data, struct fib_dp *dp)
   {
           struct radix6_data *r6 = (struct radix6_data *)_data;
   
           dp->f = radix6_lookup;
           dp->arg = r6->rh;
   
           return (FLM_SUCCESS);
   }
   
   static enum flm_op_result
   radix6_change_cb(struct rib_head *rnh, struct rib_cmd_info *rc,
       void *_data)
   {
   
           return (FLM_SUCCESS);
   }
   
   struct fib_lookup_module flm_radix6 = {
           .flm_name = "radix6",
           .flm_family = AF_INET6,
           .flm_init_cb = radix6_init,
           .flm_destroy_cb = radix6_destroy,
           .flm_dump_rib_item_cb = radix6_add_route_cb,
           .flm_dump_end_cb = radix6_end_dump,
           .flm_change_rib_item_cb = radix6_change_cb,
           .flm_get_pref = radix6_get_pref,
   };
   
   static void
   fib6_algo_init(void)
   {
   
           fib_module_register(&flm_radix6_lockless);
           fib_module_register(&flm_radix6);
   }
   SYSINIT(fib6_algo_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, fib6_algo_init, NULL);

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